Adding a submenu to header?

We're styling our Ning site, http://addivanetwork.com to integrate with our main site, http://addiva.net, which is on WordPress. It's important there's a menu somewhere intuitive that will take people back to the main site.

Is there are way to customize the header to accept something like that? I've found the 'text' widget and added it. I'm thinking, if I could use CSS to force it up onto the header, maybe I could get that to work. I've started fiddling with that, but thought it would be wise to ask here, am I going in a good direction, or is their a better/simpler way?